1. Field of the Invention
The present invention relates to an apparatus and method for generating a Low Density Parity Check (LDPC) code. More particularly, the present invention relates to an apparatus and method for controlling positions where zeros are inserted in an input information vector to support various information vector lengths during the generation of the LDPC code.
2. Description of the Related Art
Next-generation communication systems are evolving to provide various high-speed and high-capacity services to Mobile Stations (MSs). Examples of the next-generation communication system include an Institute of Electrical and Electronics Engineers (IEEE) 802.16 communication system, a Worldwide Interoperability for Microwave Access (Mobile WiMAX) communication system and an IEEE 802.11 communication system. The Mobile WiMAX communication system is a communication system based on the IEEE 802.16 communication system and the IEEE 802.16 communication system is a communication system using the IEEE 802.16 standard.
The next-generation communication system considers using Low Density Parity Check (LDPC) codes to support high-speed transmission and reception of a large volume of data. The next-generation communication system considers using the LDPC codes because the LDPC code has a simple parallel implementation that enables implementation of a decoding apparatus having high throughput, compared to other channel codes, such as, Turbo codes and convolutional codes.
Meanwhile, various schemes such as a Hybrid Automatic Repeat reQuest (HARQ) and an Adaptive Modulation and Coding (AMC) have been proposed for the next-generation communication system to support high-speed transmission and reception of a large volume of data. The communication system should support various code rates to use HARQ and AMC.
However, the LDPC codes have the following shortcomings in terms of the code rate.
Since the LDPC code is generated using a parity-check matrix with a fixed size, a length of an information vector desired to be generated with the LDPC code should also be fixed. Therefore, when a length of an input information vector is not equal to a required information vector length, which is required when the parity-check matrix is used, the length of the input information vector must be matched to a required information vector length. For example, when the length of the input information vector is less than the required information vector length, it is necessary to insert zero in the input information vector so that the length of the zero-inserted information vector may be equal to the required information vector's length.
However, positions where zeros are inserted in the input information vector have not been proposed in detail.
Therefore, a need exists for an apparatus and method for controlling positions where zeros are inserted in an input information vector.